Incandescent lamps



(Ho Model.)

J MUHRLE REPAIRING INGANDBSGENT LAMPS.

No. 541,491. Patented June 25, 1895.

UNIT D STATES PATENT OFFICE.

JOSEPH MOHRLE, OF MUNICH, GERMANY.

REPAIRING INCANDESCENT LAMPS.

SPECIFICATION forming part of Letters Patent No. 541,491, dated June 25,1895.

Application filed January 25, 1895. Serial No. 536,262. (No model.)Patented in Germany October 3, 1890, No. 58,802; in England October18,1890,No.16,613,' in France October 20,1890, No. 208,976, and February17, 1892, No. 225,731; in Belgium June 2,1891, No. 95,085; in SwedenNovember 3,1891,No. 4,011; lin $witzerland November 4, 1891, No. 4,243;in Spain November 23, 1891, No. 2,479 and No. 12,647; in DenmarkFebruary 3, 1892, No- 588/91; in Austria-Hungary March 1, 1892, No.51,994 and No, 4,471, and in Italy March 31,1892,No. 31,114.

T0 at whom it may concern.-

Be it known that I, JOSEPH MOHRLE, a citizen ot the Kingdom of Bavaria,and a resident of Munich, Bavaria, Germany, have invented certain newand useful Improvements in Repairing Incandescent Lamps, (for which Ihave received patents in the following countries: Germany, No. 58,802,dated October 3, 1890; Austria-I-Iungary, No. 51,994 and No. 4,471,dated March 1,1892; Belgium, No. 95,085, dated June 2, 1891; GreatBritain, No. 16,613, dated October 18, 1890; Den mark,No. 588/91, datedFebruary 3, 1892; Sweden, No. 4,011, dated November 3, 1891; Spain, Nos.2,479 and 12,647, dated November 23, 1891; Switzerland, No. 4,243, datedNovember 4, 1891; Italy, No. 31,114, dated March 31, 1892; France, No.208,976, dated October 20, 1890, and No.

, 225,731, dated February 17, 1892,) of which the following is aspecification.

My invention relates to an improved process of and device forinsertingnew filaments in incandescent lamps.

The object of my invention is to restore incandescent lamps in which thefilaments have been burned out or broken, whereby the lamp becomes asefficient as before. Y

My invention consists in a process for inserting and securing the newfilament in place.

The invention will first be described in connection with theaccompanying drawings and then particularly pointed out in the claims.

In the drawings, Figure 1 shows a lamp with a slot formed in the top andwith the filament removed, a new filament being shown beside it. Fig. 2shows the manner of inserting the new filament through the slot. Fig. 3shows a lamp with the new filament in place and ready to be exhausted, apipette being shown in dotted lines. Fig. 4 illustrates the new deviceemployed by me in welding the filament to the electrodes. Fig.

5 is a plan View of a lamp, showing the slot for the insertion of thefilament. trates another form of filament.

In my process, the point of the glass globe is first removed so thatonly a very small Fig. 6 illusto the passage of the current.

opening is formed. Then a slot,f, somewhat enlarged in the middle, asindicated in Fig. 5, is formed with the aid of a blow-pipe fia'me, e.e., the small opening is enlarged to form a slot whose rim extendsupward, according to Figs. 1 and 3. The old filament is then removed andthe two platinum-electrodes, x, y, are cleaned. When this is completed,the new filament, b, of any form or system whatever, is introducedthrough the slotted openaf- The attachment of the bent filament iseffected by connecting its ends to the platinumelectrodes by a plasticmass. This plastic mass is prepared from pure carbon or hard purevegetable charcoal and a solution of salts of metals fusing withdifficulty. The solutions, for example, are saturated solutions ofplatinum or copper in acids.

The preparation of the carbon to be employed for the plastic mass iscarried on in the known manner, 6. g., by forming electric arcs inbenzol or other liquid hydrocarbon, the two electrodes being slowlyseparated, and pure carbon being then deposited upon one of theelectrodes. Of course, the carbon will be obtained in this manner, whenno pure vegetable charcoal is at hand. A small portion of the mass soprepared from carbon in the solution of a metallic salt is applied tothe slightly bent electrodes and the filament pressed against the same.When the mass has hardened somewhat and the filament is in properposition, an additional quantity of the mass is applied until thefilament is completely enveloped and the electrodes do not projectbeyond the same. The lamp is then dried. After this operation, the massis rendered conducting, so as to ofier no resistance This is effected asfollows: Fig. 4 represents a simple contrivance which consists in apiece of copper wire, m, coated with an insulating substance, so thatits contact with the filament will not render the same inoperative. Atits upper end, the copper wire is connected with the circuit, while atits lower end it is provided with a small piece of carbon, preferably inthe shape of a cylinder, 0. To make the cementing mass conducting, thissmall cylinder is introduced into the lamp through the slot, asindicated in the drawings. A suitable electric current being now passedthrough the copper wire and the electrode touched with the small carboncylinder, a small electric arc is generated, which brings the mass tored inc'andescence. A passage for the current is thus established, andmade apparent by introducing an incandescent lamp into the circuit. Thesame manipulation is performed with respect to the other electrode. a

One of the essential features of my process consists in the employmentof the above-described carbon cylinder as an anode, while the electrodeto which the filament is being attached forms the cathode. In this way,the

- plastic mass is heated to incandescence, and,

at the same time, the electric current carries away small particles ofcarbon from the anode and deposits them upon the joint, thereby buildingup the same and greatly strengthening it. After the filament has thusbeen attached, the slot,f, in the lamp, is brought opposite the flame,the slot closed and the exhaust pipe or pipette, d, applied. The air isthen exhausted and the lamp sealed in the well known manner.

Fig. 3 represents the new lamp which even an expert can not distinguishfrom the usual lamp.

In suitable lamps, the connection of the ends of the filaments with theelectrodes may be carried out by means of thin platinum sleeves in theshape of tubes or helical wires of proper cross section, as shown inFig. 6, which are secured by cement, as above. This mode of connectingthe filaments with the electrodes is very secure.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. The process of restoring incandescent lamps, which consists informing an opening in the glass globe, then removing the old filament,then cleaning the electrodes and applying, to them a cement comprisingamixture of carbon and a solution of a metal salt, then inserting a newfilament into the cement on the electrodes, then drying the cement, thenapplying more cement, and finally fusing the cement by a current ofelectricity, substantially as set forth.

2. The process of restoring incandescent lamps, which consists informing an opening in the glass globe, then removing the old filament,then cleaning the electrodes and applying to them a cement comprising amixture of carbon and a solution of a metal salt, then inserting a newfilament into the cement on the electrodes, then drying the cement, thenapplying more cement, and then forming an electric are between the massof cement and a carbon anode, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed myname in presence of two subscribing witnesses.

' J. MOHRLE.

Witnesses:

ALBERT WEIOKMAN, CARL MAYOR.

